Human bile duct carcinoma cell line producing abundant mucin in vitro

A human bile duct carcinoma cell line, designated OZ, was established from ascitic effusion of a patient who suffered from obstructive jaundice due to the clogging of the common bile duct with mucinous substances secreted by the cancer cells. OZ was found to be capable of producing mucin in vitro and pools of mucin were macroscopically identified on the monolayer of the cells. On the electron micrographs, cell coat type mucin and abundant intracytoplasmic desmosomes were observed. The OZ cells secreted carcinoembryonic antigen in culture and had high enzymatic activity of gamma-glutamyl transpeptidase. The tumor heterotransplanted into nude mice also showed mucin production.     

Establishment and characterization of a cholangiocarcinoma cell line （RMCCA-1） from a Thai patient

INTRODUCTIONCholangiocarcinoma is a highly malignant epithelial neoplasm that arises within the intrahepatic and extrahepatic biliary tract[1].The pathogenesis of this disease has been strongly associated with chronic inflammation and cellular injury with…     

Establishment and characterization of a cholangiocarcinoma cell line (RMCCA-1) from a Thai patient

AIM: To establish and characterize a new cell line derived from peripheral cholangiocarcinoma of a Thai patient.METHODS: The peripheral cholangiocarcinoma specimen surgically obtained from the patient was aseptically processed by washing and mincing before culturing in Ham's F12 medium containing 10% fetal bovine serum. After 3 mo, when the cell line has become homogeneous and stabilized, several features were investigated, including growth characteristics,immunofluorescence staining for cytokeratins, expression of tumor markers, chromosomal analysis by G-banding and multicolour fluorescence in situ hybridization (mFISH), in vitro migration and invasion characteristics.RESULTS: The RMCCA-1 cell line has been established.These cells proliferated as a monolayer with a population doubling time of 48 h. Immunofluorescence staining showed positive staining for human cytokeratin 7 and 19 verifying the biliary epithelial origin. RMCCA-1secreted carbohydrate antigen 19-9 (CA19-9), but insignificant levels of carcinoembryonic antigen (CEA)and α-fetoprotein (AFP). Chromosome analysis identified aneuploidy karyotypes with a modal chromosome number of 59. RMCCA-1 exhibited a low level of in vitro invasiveness, but a high degree of motility. The cell line exhibited a significant number of chromosomal aberrations as shown by mFISH and G-banding methods.CONCLUSION: A new cell line derived from peripheral cholangiocarcinoma of a Thai patient has been established. This cell line shows a low level of in vitro invasiveness, but a high degree of motility. It will serve as a valuable tool for further studies on tumor biology,molecular pathogenesis, metastatic mechanism and response to therapeutic drugs of cholangiocarcinoma.     

In vitro establishment and characterization of a human megakaryoblastic cell line

A human megakaryoblastic cell line, designated CHRF-288-11, has been established in vitro through the use of adherent stromal cells in long-term human bone marrow culture. Long-term bone marrow cultures were required for the initial adaptation of the megakaryoblastic cells to culture conditions; however, once adapted, the cells were weaned from the stromal layer until they proliferated in the complete absence of any feeder layers. The seed cells for the establishment of this line were derived from a solid tumor; the cloned cell line derived from this tumor exhibits markers characteristic of megakaryocytes and platelets. Specifically, the cells express platelet peroxidase, platelet factor 4, and platelet Ca+(+)-adenosine triphosphatase (ATPase), glycoprotein IIb-IIIa (CDw41), factor VIII antigen, and the MY7 (CD13) and MY9 (CD33) antigens. The cells do not express the erythroid markers glycophorin A and hemoglobin, the myeloid marker myeloperoxidase, nor markers specific for T and/or B cells. The established cell line produces both basic fibroblast growth factor and transforming growth factor-beta, properties demonstrated previously for the solid tumor. The clonal cell population exhibited a unique, singular karyotype, indicating cellular homogeneity. The cells display a doubling time of approximately 33 hours in either 25% horse or calf serum. Treatment of the cells with 1 X 10(-8) mol/L phorbol 12-myristate 13-acetate (PMA) leads to the induction of multi-nucleation and hyperploidy in the cells, with approximately 35% of the cells exhibiting two or more nuclei per cell, and greater than 80% of the cells enlarging in size. The establishment of this unique cell line under defined culture conditions will be beneficial for the future study of megakaryocytic properties expressed by this cell line.     

Establishment and characterization of a new cell line derived from human colorectal laterally spreading tumor

AIM： To study the molecular mechanism of laterally spreading tumor （LST）, a cell line [Laterally Spreading Tumor-Rectum 1 （LST-R1）] was derived and the characteristics of this cell line were investigated.
METHODS： A new cell line （LST-R1） originated from laterally spreading tumor was established, Properties of the cell line were characterized using scanning and transmission electron microscopy, immunohistochemistry method, cytogenetic analysis and nude mice xenograft experiments, In vitro invasion assay, cDNA microarray and Western blotting were used to compare the difference between the LST-R1 and other colorectal cancer cell lines derived from prudent colon cancer.
RESULTS： Our study demonstrated that both epithelial special antigen （ESA） and cytokeratin-20 （CK20） were expressed in LST-R1. The cells presented microvilli and tight junction with large nuclei. The karyotypic analysis showed hyperdiploid features with structural chromosome aberrations. The in vivo tumorigenicity was also demonstrated in nude mice xenograft experiments. The invasion assay suggested this cell line has a higher invasive ability, cDNA microarray and Western blotting show the loss of the expression of E-cadherin in LST-R1 cells.
CONCLUSION： We established and characterized a colorectal cancer cell line, LST-R1 and LST-R1 has an obvious malignant tendency, which maybe partially attributed to the changes of the expression of some adhesion molecules, such as E-cadherin. It is also a versatile tool for exploring the original and progressive mechanisms of laterally spreading tumor and the early colon cancer genesis.     

Evaluation of tumor markers biochip C12 system in the diagnosis of gastric cancer and the strategies for improvement: analysis of 100 cases

BACKGROUND/AIMS: A C12 biochip system using 12 tumor markers has been developed in China for serum diagnosis of common cancers. This work is to evaluate this C12 system in the diagnosis of gastric cancer. METHODOLOGY: Sera from 100 gastric carcinoma patients were screened for 12 tumor markers including carcinoembryonic antigen, alpha-fetoprotein, carbohydrate antigen 19-9, carbohydrate antigen 242, cancer antigen 15-3, cancer antigen 125, prostate specific antigen, free-PSA, neuron-specific enolase, human chorionic gonagotropin-beta, human growth hormone, and ferritin, using the C12 biochip system. The most relevant tumor marker and the contribution of the tumor markers to the improvement of diagnosis were determined. RESULTS: The overall diagnostic rate of C12 biochip system was 37%, and 7.8%, 29.4%, 35.5% and 50%, respectively, for stages I, II, III and IV patients. The differences in diagnostic rates between stage I (7.8%) and stage IV (50%) reached statistical significance (chi-square test, Chi2=7.20, p<0.01). Among all the 12 markers, carbohydrate antigen 19-9 had the highest positive rate up to 23%, against which any form of combinations of 5 most relevant tumor markers (2, 3, 4 or 5 markers combined) could not significantly improve the diagnostic rate. CONCLUSIONS: The C12 biochip system has some value in the diagnosis of advanced stage gastric cancer, but less sensitive in early gastric cancer.     

Human intestinal goblet cells in monolayer culture: characterization of a mucus-secreting subclone derived from the HT29 colon adenocarcinoma cell line

HT29-18N2 (N2) cells, a subclone of the HT29 human colon carcinoma cell line, are shown in this report to be a model system for the study of human goblet cell differentiation and mucin secretion. Grown in the absence of glucose, these cells formed homogeneous epithelial monolayers of columnar cells with typical goblet cell morphology. Differentiation occurred on uncoated glass; laminin, fibronectin, or collagen type I or IV did not enhance differentiation. HT29-18N2 cells grown on uncoated or matrix-coated permeable filters formed differentiated monolayers, but mucin granules within some of these cells polarized along intraepithelial lumens. Polyclonal antibodies raised against purified human colonic mucin, and also a monoclonal antibody against a protease-sensitive epitope of human colonic mucin, stained secretory granules of all differentiated goblet cells within N2 cell monolayers but did not stain predifferentiated goblet cells lacking large secretory granules. Monoclonal antibodies against specific carbohydrate sequences of human mucins also failed to stain N2 cells before differentiation, but recognized varying fractions of differentiated N2 goblet cells. Autoradiographic visualization of radiolabeled glycoproteins demonstrated transport and secretion of N2 cell mucin granules. Cholinergic stimulation of differentiated N2 cell monolayers resulted in depletion of intracellular mucin granules.     

Multicellular gastric cancer spheroids recapitulate growth pattern and differentiation phenotype of human gastric carcinomas

BACKGROUND & AIMS: Advanced gastric cancer has a poor prognosis and is largely unresponsive to currently available chemotherapeutic drugs. The development of more effective therapies would be aided by better preclinical models. METHODS: An in vitro multicellular gastric cancer spheroid model was established using the liquid overlay technique and compared with the corresponding xenografts in immunodeficient mice. RESULTS: Twelve of 17 (71%) gastric cancer cell lines reflected growth characteristics of their parental gastric carcinomas in three-dimensional culture. Thus, cell lines derived from peritoneal and pleural carcinomatosis grew as single cells (HSC-39, KATO-II, KATO-III) and cell aggregates (SNU-5, SNU-16). Cell lines representing adenosquamous (MKN-1) and tubular differentiation (MKN-28, MKN-74, N87) formed partly compact multicellular spheroids recapitulating the tumor architecture of the respective original tumor. The differentiated phenotype was lost after subcutaneous implantation of the in vitro spheroids in mice. The degree of morphologic differentiation was reflected by the levels of mucin and constitutive E-cadherin expression. Heterogeneous changes of other adhesion molecules (EpCAM, alpha2beta1, CD44s, Le(x), sLe(x)) were observed. In contrast, cell lines derived from poorly differentiated gastric carcinomas (Hs-746T, RF-1, RF-48) formed fully compact spheroids mimicking the poorly differentiated phenotype, were E-cadherin negative, and showed only CD44s up-regulation. CONCLUSIONS: Recapitulating some complexity of their in vivo counterparts, multicellular gastric cancer spheroids may represent a physiologically valid model for studying the biology of this cancer, and testing new therapeutic strategies.     

Effects of epidermal growth factor on the growth of human gastric cancer cell and the implanted tumor of nude mice

AIM：Epidermal growth factor(EGF)plays an important role in the regulation of gastrointestinal tissue growth and development,and it can stimulate epithelial proliferation,cell differentiation and growth,it has been established that the EGF can promote gastric cytoprotection and ulcer healing but the potential ability of EGF to reaulate the gastric cancer growth is unknown,This study is to investigate the influence of EGF on human gastric cancer cell and the implanted tumor growth of nude mice.METHODS:The cell growth rates of human gastric adenocarinome cell lines MKN-28,MKN-45,SGC-7901 and normal human gastric epithelial cells 3T3 were assessed when incubated with recombinant human EGF(rhEGF,0.05,0.1,0.5,1.0,10,50,100mg.L^-1)using MTT method ,The cells of MKN-28,MKN-45,SGC-7901(gastric cancer tissue 1.5mm^3)were implanted in the BALB/cA nude mice for 10 days,The EGF was given intraperitoneally(15,30,60μg.kg^-1)for 3 weeks.The body weights of the tumor bearing animals and their tumor mass were measured afterwards to assess the mitogenic effect of rhEGF in the nude mice.RESULTS:Within the concentration range of 0.05-100mg.L^-1 rhEGF could increase the cell growth of normal 3T3 cells (cell growth rate 100%vs 102.8%,P&lt;0.05)but partially restrain the gastric cancer cell growth,The latter effect was related to cell differentiation ,In 15-60μg/kg rhEGF groups,the mean implanted tumor mass of MKN-28 cell were 1.75g,1.91g,2.08g/NS group 1.97g(P&gt;0.05),the mean tumor mass of SGC-7901 cell were 1.53g,1.07g,1.20g/NS group 1.07g(P&gt;0.05),and for MKN-45 cell,the tumor mass were respectively 1.92g,1.29g,1.77g/NS group 1.82g(P&gt;0.05) So rhEGF had no obvious effect on implanted MKN-28,SGC-7901 and MKN-45 tumor growth.CONCLUSION:EGF has no stimulating effect on the human gastric cancer cell growth neither in vitro nor in vivo.     

Establishment, morphological, growth and cytoskeletal properties of 135-BCA carcinoma cell line derived from lung brain metastasis

Many cell lines have been established from lung cancer but carcinoma cell lines derived from brain metastases occur rarely. The carcinoma cells growth relatively slowly in comparison with brain cells which often overgrow the tumor cells in early passages. The origin of these rapidly dividing brain cells in carcinoma cultures is discussed with respect to the previous studies on adult human brain tissue cultures. It was found that the majority of cells in adult human brain cultures derived from brain biopsies of patients with non-cancer diseases do not express glial markers. Based on the previous studies we suggest that they are glial precursor cells. The high proliferative capacity and non-glial phenotype of these brain cells may lead to the suggestion that they are of cancer origin. In this study the establishment and characterization of a new carcinoma cell line 135-BCA is described. The tissue cultures were derived from brain metastasis of lung large cell carcinoma. The cell line is specific by the epithelial cell morphology and evident cytokeratins expression during the whole subcultivation. All tumor cells were strongly immunoreactive for vimentin and negative stained for glial fibrillary acidic protein (GFAP). The new cell line may prove of value in biological and therapeutic studies of lung cancer. In addition, the further comparative analysis may reveal the environmental influence of brain tissue on carcinoma cells.     

New gastric epithelial cell lines from mice transgenic for temperature-sensitive simian virus 40 large T antigen show distinct types of cell differentiation

AIM: To develop conditionally immortalized gastric mucosal cell lines that show distinct types of cell differentiation from transgenic mice harboring temperature-sensitive simian virus 40 (tsSV40) large T antigen. METHODS: Gastric mucosal cells from the transgenic mice were cultured at a permissive temperature (33 degrees C), and proliferative cells were then cloned by colony formation. RESULTS: Eight gastric cell lines showed epithelial-like morphology and grew at 33 degrees C. Three different types of the cell lines have been established: (1) MGE12-1, MGE3-2, and MGE509 cells expressing mRNAs for pit cell markers (gastric mucin and cathepsin E); (2) MGE02, MGE503, and MGE511 cells expressing mRNAs for pit and zymogenic (pepsinogen F) cell markers, and (3) MGE507 and MGE727 cells expressing mRNAs for pit, zymogenic, and parietal (H,K-ATPase alpha-subunit) cell markers. Moreover, the TaqMan assay showed that mRNA levels of mucin, H,K-ATPase alpha-subunit, and pepsinogen F were influenced by nonpermissive temperature (39 degrees C) in MGE503 and MGE727 cells. CONCLUSION: These gastric epithelial cell lines seem to reflect different stages of development of gastric mucosal cells.     

Nonhematopoietic tumor cell lines express stem cell factor and display c-kit receptors.

Human stem cell factor (SCF) acts in the presence of other growth factors to stimulate the growth of primitive hematopoietic progenitor cells. These effects are performed by activation of the SCF receptor, c-kit. Because of the potential use of SCF in patients undergoing chemotherapy and bone marrow transplantation, the effect of SCF on nonhematopoietic tumors requires investigation. To determine whether human tumor cell lines display c-kit receptors, we performed binding experiments with 125I-SCF on a breast carcinoma cell line (Du4475), a gastric carcinoma cell line (KATO III), a melanoma cell line (HTT144), as well as two small cell lung carcinoma cell lines (H69 and H128). The biologic effect of SCF on tumor cell lines was assessed by its ability to stimulate tritiated thymidine uptake and to enhance colony growth in methylcellulose. The breast carcinoma cell line, Du4475, as well as two small cell lung carcinoma cell lines, H69 and H128, exhibit high-affinity c-kit receptors with approximate binding affinities of 40, 100, and 90 pmol/L, respectively. The number of high-affinity receptors per cell ranged from 700 to 9,500. The gastric carcinoma cell line, as well as the melanoma cell line, showed trace binding of 125I-SCF. In the presence of SCF alone, or in combination with granulocyte-macrophage colony-stimulating factor or interleukin-3, there was less than a 17% increase in the colony growth of Du4475, H69, or H128 cell lines. Postulating that the lack of growth response could be secondary to endogenous SCF production by the tumor cell lines, we used an RNAse protection assay to determine whether the tumor cell lines contain SCF messenger RNA (mRNA). In addition, we tested tumor cell line supernatants for the presence of secreted SCF protein by enzyme immunoassay, and analyzed the tumor cell lines for membrane-bound SCF by indirect immunofluorescence. Our results show that the Du4475, H69, and H128 cell lines, as well as a melanoma cell line (HTT144), have multiple copies of SCF mRNA. Soluble SCF protein was detected in the cell supernatants in the Du4475 and H69 cell lines and SCF was found on the surface of all four cell lines. These data show that some human solid tumor cell lines display high-affinity c-kit receptors and produce SCF, which can be detected on the cell surface. These results suggest the possibility that autocrine production of SCF by c-kit receptor-bearing tumor cells may enhance cell growth in tumor cell lines.     

Melanoma-associated fibroblasts modulate NK cell phenotype and antitumor cytotoxicity

Although the role of the tumor microenvironment in the process of cancer progression has been extensively investigated, the contribution of different stromal components to tumor growth and/or evasion from immune surveillance is still only partially defined. In this study we analyzed fibroblasts derived from metastatic melanomas and provide evidence for their strong immunosuppressive activity. In coculture experiments, melanoma-derived fibroblasts sharply interfered with NK cell functions including cytotoxicity and cytokine production. Thus, both the IL-2-induced up-regulation of the surface expression of NKp44, NKp30, and DNAM-1 triggering receptors and the acquisition of cytolytic granules were inhibited in NK cells. This resulted in an impairment of the NK cell-mediated killing of melanoma target cells. Transwell cocultures and the use of specific inhibitors suggested that cell-to-cell contact was required for inducing DNAM-1 modulation. In contrast, modulation of NKp44 and NKp30 was due to PGE₂ released by fibroblasts during coculture. Normal skin fibroblasts could also partially affect NK cell phenotype and function. However, the inhibitory effect of tumor-derived fibroblasts was far stronger and directly correlated with their ability to produce PGE₂ either constitutively or upon induction by NK cells.     

Analysis of gene amplification in human tumor cell lines.

Oncogene amplification has been observed in various primary tumors and tumor-derived cell lines. In several types of cancer, amplification of specific oncogenes is correlated with the stage of tumor progression. To estimate the frequency of gene amplification in other tumor types and to determine whether the ability to grow in vivo is associated with gene amplification in tumor cell lines, we have developed a modified version of the in-gel renaturation assay that detects human DNA sequences of unknown nature amplified as little as 7- to 8-fold. This assay was used to screen 16 cell lines derived from various solid tumors and leukemias. Amplified DNA sequences were detected in only one cell line, Calu-3 lung adenocarcinoma. This cell line was found to contain coamplified NGL (formerly termed neu) and ERBA1 oncogenes. However, when one of the amplification-negative cell lines, PC-3 prostatic carcinoma, was selected for in vivo growth in nude mice, amplified DNA sequences became detectable in these cells. The amplified sequences included the MYC oncogene, which showed no amplification in the parental cell line but was amplified 10- to 12-fold in the in vivo-selected cells. MYC amplification may, therefore, provide tumor cells with a selective advantage specific for in vivo growth.     

Peptides Derived from a Soluble Molecule of the Human Leukocyte Antigen (HLA) Class I Cause Apoptosis in Gastric Cancer Cell Lines

We have reported that the levels of the soluble molecule of the human leukocyte antigen class I (sHLA-I) in patients with advanced gastric cancer were significantly lower than those in patients with cancer in the early stages. However, the effect of sHLA-I on gastric cancer cells has not been elucidated. Using human gastric cancer cell lines, MKN28, MKN45, and MKN74, we evaluated the effects of sHLA-I on cell growth, DNA synthesis, and apoptosis induction. Three types of synthesized peptides derived from HLA-I were also examined for their capacity to induce apoptosis. sHLA-I and a synthesized peptide, nos. 220–232 of the α3 domain of HLA-B7, caused cell growth inhibition by inducing apoptosis in human gastric cancer cells. This peptide also inhibited the in vivo growth of cancer dissemination caused by an intraperitoneal injection of MKN45 into severe combined immunodeficient mice. In conclusion, sHLA-I and the peptides derived from HLA-I cause apoptosis in human gastric cancer cell lines.     

Tumorigenicity,invasion, and metastasis of human gastric cancer in nude mice

Summary Tumors derived from 105 patients with gastric cancer were subcutaneously heterotransplanted into nude mice in order to study their tumorigenicity and malignant behavior. Of the 105 gastric cancers, 45 were successfully transplanted (a 42.9% tumorigenesis rate). The tumorigenesis rate of Borrmann type 1 and 2 cancers (77.8%) was significantly higher than that of type 3 and 4 cancers (34.6%). Also, the tumorigenesis rate of differentiated carcinoma (57.1 %) was significantly higher than that of undifferentiated carcinoma (30.9%). Spontaneous metastases from the subcutaneous tumors were observed in 5 of the 37 established tumor lines (13.5%), and macroscopic pulmonary metastases were common with one tumor line (SCK-29). Although most of the subcutaneous gastric cancers showed local expansion without distant metastasis, the same tumor cells implanted into the peritoneal cavity exhibited invasive growth and/or metastasis. Thus, the expression of a metastatic pheno-type by human gastric cancer was influenced by the host microenvironment. The SCK-29 tumor line with its high metastatic potential may be useful for studies on the mechanism of blood-borne metastasis.Abbreviations pap papillary adenocarcinoma - tub₁ well-differentiated adenocarcinoma - tub₂ moderately differentiated adenocarcinoma - por poorly differentiated adenocarcinoma - sig signet-ring cell adenocarcinoma - muc mucinus adenocarcinoma - giant giant cell adenocarcinoma - ud undifferentiated adenocarcinoma - ade ascitic adenocarcinoma This study was supported in part by a grant-in aid for cancer research (B.no. 63480309) from the Ministry of Education, Science and Culture, Japan     

Establishment and characterization of human hilar bile duct carcinoma cell line and cell strain

We established and characterized a human hilar bile duct carcinoma (HBDC) cell line from cells isolated from the ascites of a 75-year-old Japanese woman. Histopathological findings were confirmed to be poorly differentiated adenocarcinoma (pat BsrlCm according to the Japanese Society of Biliary Surgery General rules for surgical and pathological studies on cancer of the biliary tract, 4th edn.). Using a semi-agarose method, a daughter-cell strain was also established. Both the cell line and the strain were transplanted into scid or nude mice with a 100% inoculation rate. The population doubling times of the cell line and the strain were 32.25 and 35.78 h, respectively. The cell line and strain strongly expressed human epithelial antigen (HEA)-125 and cytokeratin (CK)-19 but did not express desmin and partly expressed vimentin. High values tumor markers (carbohydrate antigen [CA19-9], Span-1, KMO-1) were detected in culture supernatants from both the cell line and the cell strain and the concentrations paralleled the patient's serum data. DNA analysis revealed that the cell strain was diploid, whereas the cell line was aneuploid, with a DNA index (DI) of 0.85. Chromosomal analysis of the cell line and the strain revealed a range of numerical abnormalities (76–93 and 74–88, respectively) as well as structural abnormalities. The establishment of this HBDC cell line and strain may provide some benefit for fundamental biological research.     

Organ-specific mucin antigens and gastrointestinal carcinogenesis.

Organ-specific mucin antigens detected by polyclonal antibodies were first used to characterize abnormal differentiation of gastrointestinal (GI) adenocarcinomas (1,2). These mucin tumour markers can thus be useful as criteria for evaluating the degree of gastric or intestinal differentiation of gastric carcinomas. In addition, some of these mucin antigens are expressed early during GI carcinogenesis where they are associated to premorphological abnormalities (3-5). Consequently, these markers are of importance for studying genetic changes occurring in precancerous mucosa, in which cancer cell transformation can occur. Finally, recent observations have pointed out a putative value of these mucin antigens for screening high risk populations for GI cancers. First of all, we shall define the words: mucin, mucin antigen (or epitopes) and organ-specificity before described abnormal antigen expression during GI carcinogenesis in the cancerous and in the precancerous mucosae and specially concerning their association with premorphological abnormalities.     

Hepatitis B surface antigen and alpha-fetoprotein secreting human primary liver cell cancer in athymic mice

A human primary liver cancer cell line which retains the property of synthesizing hepatitis B surface antigen has been successfully transplanted into nude (athymic) mice. The morphology of the heterotransplanted tumor is similar to that of a well-differentiated human primary liver cell cancer. It produces hepatitis B surface antigen, but there is no evidence of hepatitis B virion production: Hepatitis B core antigen is not detected in the PLC tissue, and serum is negative for hepatitis B e antigen. The nude mouse exhibits a resistance to the transplantation of the human primary liver cancer cells which can be modified by sublethal total body irradiation, suggesting involvement of an immunologic rejection mechanism. The heterotransplanted primary liver cell cancer also produces alpha-fetoprotein, as did the original tumor in vivo, although this marker was not detected during in vitro cell culture. The serum level of alpha-fetoprotein rises exponentially, enabling quantitative evaluation of tumor growth. The human primary liver cell cancer in nude mice provides an in vivo model for determination of tumor response to chemotherapeutic agents.